Introduction of Construction Methods
(low noise and vibration method)
Revolution of All Casing Method Casing Interior Rotary-type Hydraulic Hammer Grab『AK Hydraulic Catcher』
AK method does not use conventional hammer grab method which excavates using the impact of free fall. Instead of it, after gently putting AK hydraulic catcher at the bottom of the casing, it excavates using the rotation and pushing force of all-round rotation excavator. So it has low level of noise and vibration.
All hydraulic cylinders which are used for pressure bonding for the main body and the casing and used for opening and closing the shell are driven by wire. Because of this, the method does not require any hydraulic hoses or units, it is a type of hydraulic hammer though.
|NETIS registration number
Rotates the catcher in the casing using the force of the all-round rotation excavator.
Excavation with "low vibration and noise" is available.
- Focus on safety
By its excavation which done by rotating its catcher at the lowest position of the casing, safe construction is achieved.
- Massive excavation
By utilizing torque and pushing force of the all-round rotation excavator, "certain" and "massive" excavation is achieved.
- No problem with water level
Not like free-fall style hammer, there is almost no problem on water resistance even when it was used with high water level.
- Applicable to any soil properties
Since it has wide opening of its shell in the catcher, it is suited with any soil properties.
- Applicable by using wire
Since it does not use hydraulic hose or unit, and its main body is operated only by "wire", there is no risk of oil leakage.
Also it is economical because its cycle time is close to conventional hammer.
|Comparison of construction methods
Hammer grab (wire hammer)
|＜AK Hydraulic Catcher＞
- Free fall of hammer grab in the casing
Blade is penetrated in to the ground with its collision…High vibration and noise
- When the water level is high, the hammer is affected by resistance of the water, so its excavation power declines.
- Big noise at the time of soil removal (Noise due to Crown)
- Gently put a catcher in the casing ...No vibration
- After the landing, tension the wire a little. The extension devise pushes the casing and fixes the machine in the place.
- Rotate/ push-in the casing ...No noise from hammer.
- Stop the casing and loosen the 1st wire and detach the extension devise from the casing.
- Pull the second wire and close the shell with a cylinder and remove the soil.
- Pull the first and second wires at the same time to pull up the main body.
- Soil will be removed only by putting the machine on the ground ...No noise at the time of soil removal.